Mcafee AV products have falseley detected a problem with svchost.exe and then removes the false threat.
The updates since Wednesday, April 21st (DAT 5958).
How to Fix Mcafee DAT 5958 False detection
The Mcafee fix available from Mcafee's website http://service.mcafee.com/FAQDocument.aspx?id=TS100969&cid=77152, boot to safe mode and run the the downloaded file!
This involves downloading to another machine and using a cd etc to take to the affected machine. The fix worked a treat.
All the fix does is clear the problem update and reinstates the SVCHOST.exe file.
This is a major issue for Mcafee, but they have put their hands up, it is going to cost customers time and money to rectify. The fix worked a treat on a single user home pc I am glad I haven't to fix a whole corporate network.
Mcafee offer free support for those users effected, it appears a link has been made available in the on line support area (once you have logged in).
There may be an offer to get a free extension on the product, but you will need to apply within 30 days of the released update Wednesday, April 21st (DAT 5958).
If you need support from Mcafee they have contact details ref this DAT 5958 issue.
The symptom I saw were no network, windows defender error, Mcafee woud not open, internet explorer and other network applications
The scare merchants are now trying to cash in on the issue with a range of spam emails been sent.
I use sophos at work and AVG antivirus at home.
Link to Graham Cluley’s blog at Sophos a great source of Security information